The Washington Nationals got what third baseman Ryan Zimmerman called "the best possible news" on Wednesday when an MRI on his right shoulder didn't reveal significant damage.

The MRI, taken Tuesday, confirmed the diagnosis of the Nationals' team doctors that there was some inflammation in the AC joint that has been causing soreness when Zimmerman hits. A cortisone shot, injected Saturday, hasn't yet had the desired effect but that, combined with rest, is the main treatment.

He will rest the shoulder one more day before testing it with hitting Thursday. If there isn't enough improvement, the Nationals will then send him to D.C. to receive treatment from team medical director Wiemi Douoguih, including possibly another cortisone injection. A stint on the disabled list would be "more than likely," manager Davey Johnson said.